Automatic two directional belt training troughing idler assembly



Oct. 16, 1962 c, J. ARNDT ETAL 3,053,575

AUTOMATIC TWO DIRECTIONAL BELT TRAINING TROUGHING IDLER ASSEMBLY 2 Sheets-Sheet 1 Filed Nov. 20, 1959 5 m m w m Charles J. Arndt BY Ralph F Risse 3,058,575 NING Oct. 16, 1962 c. J. ARNDT ETAL AUTOMATIC TWO DIRECTIONAL BELT TRAI TROUGHING IDLER ASSEMBLY 2 Sheets-Sheet 2 Filed Nov. 20, 1959 IIIIIIII INVENTORS. Charles J. Arndt Ralph F' R1336 mm- Ea Fig. 6

Fig. 9

United States Patent Ofiflce 3,58,575 Patented Get. 16, 1962 This invention relates to flexible strand conveyors, and particularly to an automatic training idler assembly for such conveyors which automatically repositions a conveyor belt on the assembly as it passes thereover in a detrained condition.

Flexible strand conveyors of the type illustrated in the Craggs et al. Patent No. 2,773,257 have come into widespread use in recent years due to their many inherent desirable features. Among these features are high carrying capacity, low cost, and ease of installation and maintenance.

This type of conveyor generally comprises a pair of flexible rope sideframes such as Wire ropes which are strung along a conveying course such as a mine run or the like. The strands are supported at suitable intervals by support structures such as the telescoping support stands shown in the Craggs et al. patent, or by root bolts or other overhead supporting means. A plurality of conveying idler assemblies are suspended from the strands at generally equal increments therealong to form a bed for the conveying reach of the flexible belt. Return roll-er assemblies, which may be suspended from the flexible rope side frames or by independent supporting structure such as the flexible rope side frame support stands, are likewise located at intervals along the conveyor to furnish support for the return reach of the belt. Usually the return roller assemblies are spaced at considerably greater distances than the conveying idler assemblies since they support no load other than the weight of the belt itself.

Maintaining the belt centered or trained on the conveying idler assembly in a flexible rope side frame conveyor is a problem common to all rigid and non-rigid conveyor installations. As a belt passes over a roller, the resultant friction between the two moving surfaces generates a training force which is directed generally perpendicularly to the longitudinal axis of the roller. If the roller is improperly installed or knocked out of line after installation by any one of a number of causes such as falling rock or by being bumped with machines, the training efiect may be exerted in a detraining direction.

Accordingly, the primary object of this invention is to provide an automatic belt training idler assembly which automatically repositions or retrains the belt as it passes thereover in a detrained condition.

Another object is to provide an automatic belt training idler assembly utilizing a pair of conveying roller assemblies which imparts, as compared to a single roller assembly, a double training effect to the belt for any given increment of inclination of the idler assembly.

Yet a further object is to provide a belt training idler assembly which automatically repositions a belt on the assembly as it passes thereover in a detrained condition and which does not increase the width of the conveyor.

A further object is to provide a belt training idler assembly which automatically repositions a belt on the assembly as it passes thereover in a detrained condition and which does not project outwardly beyond the boundaries of the conveyor.

Yet another object is to provide an automatic belt training roller assembly utilizing a pair of training roller assemblies mounted in tandem fashion, and movable to positions substantially displaced from the perpendicular with respect to the direction of belt travel.

Other objects and advantages of the invention will become apparent from the following description and drawlogs.

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

FIGURE 1 is a top plan view with the belt omitted of one embodiment of the invention;

FIGURE 2 is a view taken substantially along the line 22 of FIGURE 1;

FIGURE 3 is a detailed, sectional view on an enlarged scale taken substantially along the line 33 of FIGURE 1 illustrating the connection of a guide roller to the end brackets;

FIGURE 4 is a diagrammatic View of a modification of the invention;

FIGURE 5 is a diagrammatic representation of another modification of the invention;

FIGURE 6 is a diagrammatic representation of the relative positions of the training roller assembly and the belt when the belt is detrained to the left;

FIGURE 7 is a diagrammatic representation of another embodiment of the invention in which the bracket pivot points are located inwardly with respect to the ends of the roller assemblies;

FIGURE 8 is a modification of the structure diagrammatically illustrated in FIGURE 7; and

FIGURE 9 is a further modification of the structure diagrammatically illustrated in FIGURE 7.

Like reference numerals will be used to refer to like parts throughout the following description of the drawmgs.

In FIGURE 1, a pair of flexible side frames in a flexible strand conveyor of the type illustrated in the Craggs et al. Patent No. 2,773,257 are indicated at 10 and 11. A pair of V-shaped brackets indicated generally at 12 and 13 are pivotally connected to the strands by pivot pin assemblies 14 and 15 Welded or otherwise secured to suitable rope clamps 16 and 17. Since the exact structure of the clamps does not, as such, form a part of the invention, it is not further illustrated.

The details of the securement of bracket 13 to rope clamp 17 is illustrated best in FIGURE 3. The pin assembly includes a base 18 welded as at 19 to the top of the clamp. The reduced shank portion 20 of the pin passes upwardly through aperture 27 in the end bracket. Vertical travel of end bracket 13 along the pin is prevented by washer 21 and cotter pin 22. The connection of the end brackets to the clamps is not so tight as to prevent relatively free rotational or swinging movement of the bracket about the pin.

Each end bracket 12 and 13 includes forwardly, inwardly directed arms 23 and 24, respectively, and rearwardly, inwardly directed arms 25, 26, respectively. The terms forwardly and rearwardly are used with respect to the direction of belt travel, which direction is indicated generally by the arrow T. Inwardly is used in the sense that a projection extending from one flexible strand toward the other is directed inwardly toward the longitudinal axis of the conveyor.

The terminal ends of legs 23-26 are notched to receive generally L-shaped connecting lugs 30, 31, 32 and 33. Lug 31 is welded to leg 24, as illustrated at 34 in FIG- URE 3, and its inwardly extending portion is slotted to form a pair of parallel cars 35 and 36, shown best in FIG- URE 2; The inwardly extending portion of connecting lug 30 is similarly slotted to form a pair of cars 37 and 38.

A troughing roller assembly of the sausage type similar to that illustrated in the Craggs et al. patent is indicated for movement in a generally vertical plane by chain links 47, 48 which are secured by suitable pins, not numbered, to the shaft ends.

The outer ends of the wing roller shafts 45, 46 are received between the parallel ears or flats 37, 38 and 35, 36 and held in place thereby connecting pivot pins 49 and 50. The roller assembly assumes a troughing contour which supports the conveying reach 51 of a flexible conveyor belt, as best illustrated in FIGURE 2.

A similar troughing roller assembly is indicated generally at 52. In brief, it consists of a center load carrying roller 53 flanked by wing rollers 54 and 55 whose shafts 56 and 57 are connected at their outer ends by pins 58 and 59 to connecting lugs '32. and 33. Those portions of each of the lugs which extend generally parallel to the longitudinal axis of the conveyor are apertured as at 60. Aperture 60 in downstream lug 31 receives shaft 62 which carries guide roller 64. A similar guide roller 63 is carried by lug 30, but for purposes of explanation, a description of roller 64 will suflice, since the rollers are substantially identical.

Roller 64 rotates in a pair of ball bearings 65, 66 held in spaced relationship by sleeve 67 surrounding shaft 62. Bottom bearing 66 rests on a pairof bearing rings, not numbered, the center ring in turn resting on a spacer 68. A cotter pin 69 or other suitable securing means prevents unintended vertical movement of the shaft 62 and consequently the roller 64.

. Variations of the basic assembly illustrated in FIG- URES 1 through 3 are shown in FIGURES 4 and 5.

In FIGURE 4, the center roller of the upstream roller assembly and the wing rollers of the downstream roller assembly have been eliminated. Likewise, in FIGURE 5,

the wing rollers of the downstream troughing roller assembly have been eliminated. In all other respects, these embodiments are substantially identical to that illustrated in detail in FIGURES 1 through 3, and accordingly the other structural connections have been indicated only diagrammatically.

In FIGURES 7, 8, and 9, modifications of the invention are illustrated in which the pivotal points of connection of the end brackets to the flexible strands of the conveyor or other support means lie inwardly from the ends of the brackets joining the roller assemblies to the end brackets.

Thus, in FIGURE 7, downstream troughing roller assembly 40 is pivotally connected to the end brackets 70 and 71 at 72 and 73; The end portions of upstream troughing idler assembly 52 have likewise been connected to end connecting brackets 70, 71 at 74, 75. The brackets are pivotally connected as at 76, 77 to suitable supporting structures such as the flexible strands or other supporting means. The pivotal bracket connecting points 76 and 77 lie between a line passing through points 74, 72 and another line passing through points 73, 75. Guide rollers 78, 79 are connected to the upstream legs of end brackets 70, 71 in substantially the same manner as illustrated in detail in FIGURE 3.

In FIGURE 8, the center roller of the upstream roller .assembly and the wing rollers of the downstream roller 4 assembly due to the action between the underside of the belt and the rollers in the assembly.

In FIGURES 1 and 2; upstream and downstream troughing roller assemblies 40, 52 are pivotally connected to end brackets 12 and 13 which in turn are pivotally connected to the strands 10 and 11 as at 14 and 15. When the conveying reach 51 of the flexible conveyor belt passes over the assembly in the centered or trained position illustrated in FIGURE 2, the two troughing idler assemblies will assume the position illustrated in FIG- URE 1. g

It is well known that a roller over which a flexible belt passes exerts a training effect on the belt. This training effect may be stated, in general, to be exerted in a direction generally perpendicular to the longitudinal axis of the roller. So long as the direction of belt travel and the direction of the training force between roller and belt are parallel, the belt will not move from side to side along the assembly. If the roller is canted at an angle to the belt and the direction of the training force for-ms an angle with the direction of belt travel, the belt will tend to move in the direction of the training eliect until it reaches a condition of equilibrium on the roller.

Thus, in FIGURE 1, for example, the direction of .travel T of the conveyor belt 51 and the direction in which the training effect or force F is exerted are parallel, and the belt will run centered over the entire assembly, as illustrated in FIGURE 2. In this condition, the belt will not contact the guide rollers 63, 64 and corresponding rollers in each of the troughing roller assemblies 40, 52 will line up with one another.

FIGURE 6, however, illustrates the condition of the troughing idler assembly when the belt is detrained. In the instantaneous position shown, the belt has detrained to the left until its edge contacts guide roller 63. Since the end brackets 12 and 13 are pivotally connected to the flexible strands and to the troughing idler assemblies, respectively, the downstream assembly tends to shift to the left under the impact of the belt against the guide roller while the upstream assembly conversely shifts to the right. As a consequence, the training effect P is directed at a slight angle to the direction of belt travel T, as illustrated by the divergent arrows in FIGURE 6. The training efiect P will gradually force the belt to the right, and, as the belt moves to the right, the entire assembly will move back to the position illustrated in FIGURE 1. The same condition will be maintained when the conveyor detrains to the right.

In FIGURES 7 through 9, variations of the basic invention are shown in which the pivotal connecting points of the end brackets to the flexible strands lie inside the points of connection of the troughing idler assemblies to the end brackets. In this instance, the guide rollers 78, 79 are located on the upstream troughing idler assembly.

As the belt detrains to the left as viewed in FIGURE 7, due to any one of a multitude of reasons including improper =belt loading, poor belt splices or a kink in the belt, it strikes guide roller 78 and moves it along the path indicated by the dotted arrow 80 since the roller is pivoted about connecting point 76. At the same time,

right guide roller 79 moves along the path indicated by dotted arrow 81 since it is pivoted about connecting point 77. The end result is to swing or twist the entire assembly into a training position in which the training force indicatedby the dotted arrow F is oriented into a retraining position, very similar to the result illustrated in FIG- URE 6.

In FIGURES 4 and 5, and 7 and 8, variations are shown in which certain rollers in the troughing roller assemblies are omitted. The training eflect of the assembly is not reduced substantially so long as at least one center primary training roller and a pair of wing rollers are retained. These embodiments have the further advantage of being somewhat lighter in weight than the structure illustrated in FIGURE 1, for example, but it is often desirable to utilize two complete idler assemblies in order to provide maximum stability for the belt.

One of the important features of the invention is the fact that a considerably greater twist can be imparted to the roller assemblies than is possible in present two direction training roller assemblies whose center or intermediate rollers remain substantially transversely positioned with respect to the direction of belt travel. With the present structure, the assemblies can be positioned at training angles of 7 or 8 or even higher, as contrasted with training angles of only approximately 2 attainable with many present two direction training roller assemblies. Actually, the training effect imparted to the belt may be considerably greater than three to four times the amount obtainable with present training assemblies since the center or intermediate roller as well as the wing rollers are re-oriented into a training position. It is only necessary therefore to place one of these assemblies in a conveyor line every 100 to 150 feet depending on the particular operating conditions, and the balance of the conveyor may consist of standard assemblies Anther important feature is the fact that this training effect is achieved without increasing the width of the conveyor, since in the embodiments shown in FIGURES 1 through 6, all of the structure lies between the strands. A single roller assembly exerting a similar effect would require either supporting structure wider than the gauge of the strands or a special relatively expensive roller positioning framework.

A further important feature is the fact that a pair of roller assemblies are secured to the strand in training relationship by only a single pair of connectors. In many current schemes for automatically training the belt as it passes over the roller assembly each troughing idler assembly requires a pair of strand connecting devices.

The foregoing description is illustrative only and not definitive. Accordingly, the invention should not be limited except by the scope of the following appended claims.

We claim:

1. An automatic belt training troughing idler assembly for a flexible sideframe conveyor having a pair of longitudinally extending side strands, said troughing idler assembly including, in combination,

a pair of end frame members,

first pivot means adapted to connect each of said frame members to a corresponding side strand which enables each frame member to pivot relative to its associated side strand,

first and second elongated roller means and second pivot means connecting the end portions of each of said first and second roller means to the end frame members in spaced, generally parallel tandem relationship substantially transversely of the strands to thereby enable the roller means to move in substantially transversely opposite directions with respect to one another and to freely assume canted positions with respect to the longitudinal axis of the conveyor in response to movement of a belt therecross in on off-center condition to thereby automatically urge the belt to a centered position.

2. The assembly of claim 1 further characterized in that said end frame members are generally V-shaped elements, said first pivot means being located adjacent the apex of each of said V-shaped elements and the second pivot means being located adjacent the free end of each leg of said V-shaped elements.

3. An automatic belt training troughing idler assembly for a flexible sideframe conveyor having longitudinally extending side strands, said troughing idler assembly including, in combination,

a pair of end frame members,

first pivot means connected to each of said end frame members substantially at their midpoints, .said first pivot means being adapted to connect said end frame members to corresponding side strands for pivotal movement relative thereto,

first and second elongated roller means,

second pivot means for pivotally connecting the end portions of each of said first and second roller means to corresponding end frame members in spaced, generally parallel tandem relationship substantially transversely of the side strands to thereby enable the roller means to move in substantially transversely opposite directions with respect to one another and to freely assume canted positions with respect to the longitudinal axis of the conveyor in response to movement of the belt thereacross in an elf-center position, said first pivot means being located transversely out- Wardly from the second pivot means.

4. An automatic belt training troughing idler assembly for a flexible sideframe conveyor having longitudinally extending side strands, said troughing idler assembly including, in combination,

a pair of end frame members,

first pivot means connected to each of said end frame members substantially at their midpoints, said first pivot means being adapted to connect said end frame members to corresponding side strands for pivotal movement relative thereto,

first and second elongated roller means,

second pivot means for pivotally connecting the end portions of each of said first and second roller means to corresponding end frame members in spaced, generally parallel tandem relationship substantially transversely of the side strands to thereby enable the roller means to move in substantially transversely opposite directions with respect to one another and to freely assume canted positions with respect to the longitudinal axis of the conveyor in response to movement of the belt thereacross in an off-center position,

said first mentioned pivot means being located transversely inwardly from the second pivot means.

5. The assembly of claim 3 further characterized by and including a pair of generally vertical axised belt guide rollers carried by said end frame members, said guide rollers being located adjacent the end portions of the downstream one of said roller means.

6. The assembly of claim 5 further characterized by and including a pair of generally vertical axised belt gudie rollers carried by said end frame members, said guide rollers being located adjacent the end portions of the upstream one of said roller means.

References Cited in the file of this patent UNITED STATES PATENTS 1,770,957 Veale July 22, 1930 1,927,849 Roberts Sept. 26, 1933 6 1,963,099 Robins June 19, 1934 2,892,534 Ogden June 30, 1959 2,983,364 Lo Presti May 9, 1961 

